Warren Ackerman is a character in the novel Final Destination: Dead Man's Hand. A tough-as-nails detective for the Las Vegas Metropolitan Police Department, he was a survivor of the Merlin's Tower elevator accident and Shawna Engels's boyfriend. Warren and his partner Isabelle Montoya were assigned to a case involving a child murdering one morning, a case that deeply disturbed Warren as he began to ponder who would beat a ten-year-old to death and why. The detectives went over to interrogate the boy's mother, Carolina Lavirra, where she told them that her boyfriend Roberto Diaz had a habit of teaching Danny some manners, and implying that he was abusive. Neither of them managed to get her to confess what happened to Danny, but they had their suspicions of Diaz. While on break, Warren shared lunch with Shawna at one of their favorite diners, first talking about how the lead dancer at Merlin's Tower was being a pain for Shawna, before the conversation digressed and Warren knew Shawna was upset over the giant felines she despised. He assured her that there was nothing to fear due to the professional trainers who worked on the cats, and jokingly told her that if one ever bothered her again, to tell it that her boyfriend's a cop. As he left the diner and regrouped with Izzy in the parking lot, they began to talk about the case a little more, before Izzy confessed that Warren never tells Shawna anything about his job. After arguing briefly, Warren agrees that they should talk more over dinner, and planned to take Shawna to Merlin's Tower.
After their unsuccessful search for Diaz, Warren confirmed with Izzy that evening that he was planning on retiring once the case was finished, this time meaning it. Afterwards, he had dinner with Shawna, but unfortunately was unable to tell her about his job because he was too busy comforting her about the incident earlier, where a panther's restraints came undone and she was nearly attacked by the feline. After eating, Warren and Shawna went into an elevator, where a woman named Allie Goodwin-Gaines freaked out about a premonition she had about everyone dying once the elevator plunged to the ground due to neglected maintenance. Warren announces he's a police officer and to stop the commotion before suffering a consequence for disturbing the peace, but Allie continues to scream for everyone to get out. Allie stops on the nearest floor and begins to climb out when the elevators slam shut and nearly cut her in half, making Warren slightly skeptical that she was lying. Arlen Ploog manages to set her free and Warren, Shawna, Ploog, Allie and her husband storm outside. While waiting, they look outside and witness the elevator falling several stories to the ground, the people inside screaming horribly as they fell.
After being interrogated by Special Agent Hotz and McGavin Warren and the other survivors traveled through the city inside a police van, where Warren banters Ploog for not speaking up earlier when he ran into Diaz, and also accidentally telling Shawna about his case. While driving, a wayward traffic light swings down and plows through the side of the van, killing the driver and critically injuring Izzy. Warren was knocked out for a brief moment before Allie woke him up and he realized the van was going out of control. Unable to get his seat belt undone, he shoots off Allie's and she was able to stop the van seconds before it crashed into a tank truck. The survivors went to the hospital shortly after the incident, where Warren furiously banters Ploog again for not speaking up about Diaz. He also learned that his partner Izzy was in severe condition and his girlfriend only received a minor injury, and was going to be okay. Later that day, Warren finally finds where Diaz is hiding and leaves the police station, unaware that his girlfriend had been in an accident.
Warren was the second survivor of the Merlin's Tower accident to die.
While on a stakeout of Roberto's cousin's house, Warren receives a call from his boss Lou Summers that his girlfriend had been killed in a terrible accident. After crying for a brief moment, he finds Diaz walking out the house. Suddenly angry, Warren approaches the man immediately before he starts shooting at him. He chased him down an alleyway and the two exchanged fire before Diaz hid behind a large container, waiting to kill the detective. Warren was suddenly blinded by a wayward newspaper and knocked over a bottle, prompting Diaz to kill him. Warren dived sideways and shot Diaz five times, killing him, even though he never found out why he murdered Danny in the first place. After he dies, the wind begins to blow and Warren looks up and notices a power line is loose after being hit by a stray bullet, and it falls out of socket. Warren also realizes he's standing in a puddle of urine and before he can move, the power line lands in the puddle and on his body and electrocutes him to death.
- Warren almost died when a van he was traveling in nearly crashed into a tank truck after the driver was killed.
- The Roberto Diaz case was to be Warren's last, he intended to retire after bringing the child killer to justice.
- After hearing about Shawna's death from his captain while staking out Roberto's hideout, Warren remembers a quote by Stephen Hawking he had once read on his partner's computer - "Not only does God play dice with the universe, he sometimes casts them where they can't be seen".
- While chasing Roberto, Warren notices how abnormally gusty it has become, despite the weather forecast making no mention of a windstorm approaching. This same wind is what causes the damaged power lines to drop down and electrocute Warren.
- Warren was always reminded that Death is a part of life.
- All the survivors of the Merlin's Tower accident died out of order. Why this happened is unclear.